Branchlight — Offline Dialogue Editor & Story Checks

Write a branch. Walk its paths. Catch what you missed.

Branchlight combines a small dialogue editor, reader preview and graph checker in one offline workbench. Open index.html from the unzipped folder in a desktop browser.

Included in the $1 download

• Edit up to 250 passages with 10 choices each; search, rename IDs and select a start passage.
• Playtest branches with restart, back and play-from-selection.
• Check broken links, duplicate IDs, missing starts, empty labels, unreachable passages and passages with no route to an ending.
• Export project JSON, a standalone playable HTML story and a localization CSV handoff.
• Browser-local autosave when available, bounded undo/redo and a read-only connection map.
• Readable source, documentation and an original nine-passage, three-ending example.

Try the free sample first

The last ferry is a playable HTML story exported from the editor. The sample demonstrates the reader output; the paid download contains the full editor and checker.

Scope and limitations

Unconditional branching only: no variables, conditions, inventory, engine plugins, Twine/Yarn/Ink import, cloud sync or collaboration. CSV is export-only. JSON uses the documented branchlight/1 schema. Graph checks do not assess writing quality. The map is read-only, not a draggable graph editor.

Autosave belongs to your browser/profile and can be unavailable for local files. Save JSON regularly as your portable backup. Tested in desktop Chrome; other browsers are not verified.

Commercial work and privacy

You retain your rights in your own stories. You may distribute playable exports in commercial projects under the included license. Tool/source resale is not permitted. No network calls, telemetry, external font files or third-party libraries are used by the app.

AI disclosure

Code, example story and documentation were created with generative AI assistance.